PURPOSE: To easily obtain an alloy capable of deboronizing treatment in a shorter time than conventional one and also excellent in etching characteristic by subjecting an Fe-Ni alloy containing specific amounts of B to hot rolling and then to deboronizing treatment in the prescribed atmosphere.

CONSTITUTION: An alloy having a composition consisting of, by weight, 30-60% Ni, 0.001-0.1% B, and the balance essentially Fe is hot-rolled, and the resulting hot rolled stock is subjected to deboronizing treatment at 700-1200°C in an atmosphere having a dew point between -10°C and 40°C and composed essentially of hydrogen in the stage before, in the course of, or after cold rolling. If necessary, Co is further added to the above composition by 5-20%.